How to fix error when extending Django User Model?

Question

Django

Good day. I do the example as on habrahabr
Using a one-to-one connection with the user model (user profiles)

models.py
from django.db import models
from django.contrib.auth.models import User

class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    bio = models.TextField(max_length=500, blank=True)
    location = models.CharField(max_length=30, blank=True)
    birth_date = models.DateField(null=True, blank=True)

Now let's add some magic: define signals so that our Profile model is automatically updated when the User model data is created/changed.

from django.db import models
from django.contrib.auth.models import User
from django.db.models.signals import post_save
from django.dispatch import receiver

class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    bio = models.TextField(max_length=500, blank=True)
    location = models.CharField(max_length=30, blank=True)
    birth_date = models.DateField(null=True, blank=True)

@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    if created:
        Profile.objects.create(user=instance)

@receiver(post_save, sender=User)
def save_user_profile(sender, instance, **kwargs):
    instance.profile.save()

We hooked create_user_profile() and save_user_profile() to the save event of the User model. Such a signal is called post_save.
And now an example of a Django template using Profile data:

<h2>{{ user.get_full_name }}</h2>
<ul>
  <li>Username: {{ user.username }}</li>
  <li>Location: {{ user.profile.location }}</li>
  <li>Birth Date: {{ user.profile.birth_date }}</li>
</ul>

Error when I click save form

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8001/profile/

Django Version: 1.9.8
Python Version: 3.6.0
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'blog']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback:

File "C:\Python36\lib\site-packages\django\core\handlers\base.py" in get_response
  149.                     response = self.process_exception_by_middleware(e, request)

File "C:\Python36\lib\site-packages\django\core\handlers\base.py" in get_response
  147.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Python36\lib\site-packages\django\contrib\auth\decorators.py" in _wrapped_view
  23.                 return view_func(request, *args, **kwargs)

File "C:\Python36\lib\contextlib.py" in inner
  53.                 return func(*args, **kwds)

File "C:/skript/untitled2\blog\views.py" in update_profile
  20.             messages.success(request, _('Your profile was successfully updated!'))

Exception Type: NameError at /profile/
Exception Value: name '_' is not defined

if I remove the underscores another error occurs

Traceback:

File "C:\Python36\lib\site-packages\django\core\urlresolvers.py" in reverse
  586.                 extra, resolver = resolver.namespace_dict[ns]

During handling of the above exception ('settings'), another exception occurred:

File "C:\Python36\lib\site-packages\django\core\handlers\base.py" in get_response
  149.                     response = self.process_exception_by_middleware(e, request)

File "C:\Python36\lib\site-packages\django\core\handlers\base.py" in get_response
  147.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Python36\lib\site-packages\django\contrib\auth\decorators.py" in _wrapped_view
  23.                 return view_func(request, *args, **kwargs)

File "C:\Python36\lib\contextlib.py" in inner
  53.                 return func(*args, **kwds)

File "C:/skript/untitled2\blog\views.py" in update_profile
  21.             return redirect('settings:profile')

File "C:\Python36\lib\site-packages\django\shortcuts.py" in redirect
  116.     return redirect_class(resolve_url(to, *args, **kwargs))

File "C:\Python36\lib\site-packages\django\shortcuts.py" in resolve_url
  204.         return urlresolvers.reverse(to, args=args, kwargs=kwargs)

File "C:\Python36\lib\site-packages\django\core\urlresolvers.py" in reverse
  596.                                          key)

Exception Type: NoReverseMatch at /profile/
Exception Value: 'settings' is not a registered namespace

Answer 1

No need to do one-to-one for 7-8 years. Django allows you to use your own user model since hell knows when, where do these ideas about what to do profiles or through one-to-one in 2017 still come from? ... This was necessary in the first versions of Django in 2006-2007 then there was no other way.
If you found this on any site on the net, please write to the author to correct the information. Because such questions regularly arise here due to the fact that people, without understanding, begin to fence these crutches and shoot themselves in the legs.

Answer 2

birth_date = models.DateField(null=True, blank=True)

Tell us why you need null=True and blank=True here